The present invention relates broadly to a target tracking system and in particular to a tracking apparatus for measuring the position and dimensions of a target.
In the prior art, the target gate was adjusted on the basis of the gated portion of the target and not by the total target dimension. Thus, a prior art tracker apparatus would command the tracker gate to center itself on the portion of the target which is within the target gate within 1/60 of a second. The target gate, by a rather slow and tedious process of halving the error, would adjust its size to enclose the portion of the target which is in its view until the entire target is enclosed. Until the present time, the maximum theoretical tracking rate was limited to a 1/2 gate width dimension per field. In the present invention, the theoretical tracking rate has been shown to be 1 gate dimension. Thus, as long as some portion of the target is within the viewing apperture of the target gate, the tracker can snap the gate over the entire target in one field.